鲆鲽类线粒体基因排列、特征比较及系统发生分析  

Gene Order,Characteristics and Phylogenetic Analyses of Mitochondrial Genomes in Flatfish Pleuronectiformes

作　　者：申欣[1,2] 田美[1] 孟学平[1] 程汉良[1] 许建和[1] 阎斌伦[1] 

机构地区：[1]淮海工学院海洋学院江苏省海洋生物技术重点实验室,江苏连云港222005 [2]中国科学院北京生命科学研究院,北京100101

出　　处：《水产科学》2013年第10期590-596,共7页Fisheries Science

基　　金：国家自然科学基金资助项目(40906067);香江学者计划项目(XJ2012056);中国博士后科学基金资助项目(2012M510054;2012T50218);中央财政支持地方高校发展专项资金资助项目(CXTD04;CXTD01);江苏省海洋生物技术重点实验室资助项目(2009HS13;2011HS009);江苏省"青蓝工程"人才基金资助项目(苏教师[2010]27号)

摘　　要：鲆鲽类线粒体基因组的基因组成非常保守,均编码37个基因。鲽亚目线粒体主编码链的A+T含量较低,介于53.21%(星斑川鲽)与55.78%(大菱鲆)之间。鳎亚目舌鳎科的两个物种(短吻舌鳎和半滑舌鳎)线粒体主编码链的A+T含量较高,分别达到60.35%和60.59%;而鳎亚目鳎科的塞内加尔鳎线粒体主编码链的A+T含量与鲽亚目物种非常接近,为54.63%。庸鲽属、星鲽属和舌鳎属线粒体蛋白质编码基因的非同义替换率(Ka)与同义替换率(Ks)的比值(Ka/Ks)最低为0,最高为0.2171,表明在鲆鲽类线粒体基因组中存在较强的纯化(负)选择。鲽亚目的9个物种及鳎亚目鳎科的塞内加尔鳎线粒体基因组与脊椎动物线粒体基因组的典型排列方式完全一致。然而,鳎亚目舌鳎科的短吻舌鳎和半滑舌鳎线粒体基因组与此相比,均存在一个tRNA基因(trnQ)的易位与倒位。综合分析12种鲆鲽类内部线粒体单基因的变异位点特征,nad5、nad4和nad2基因是较为理想的分子标记。基于线粒体基因组构建的鲆鲽类系统发生结果支持其在科阶元的亲缘关系为:{[(鲽科+牙鲆科)+菱鲆科]+鳎科}+舌鳎科。鳎亚目的鳎科先与鲽亚目聚类(BPN=100,BPM=100),随后与舌鳎科聚类(BPN=100,BPM=100),从而将鳎亚目分为2支,综合线粒体主编码链的A+T含量与基因排列等基因组特征,鳎亚目是否为单系群受到质疑,值得今后进一步研究来确定。T he gene content of mitochondrial genomes is highly conserved （each encoding 37 genes ） in flatfish Pleuronectiformes .The A ＋ T contents of mitochondrial main coding strands from the suborder Pleuronectoidei ,ranging between 53 .21% （starry flounder Platichthys stellatus ） and 55 .78% （turbot Scophthalmus maximus ） , were lower than those from the suborder Soleoidei . The maximal A ＋ T contents were observed in family Cynoglossidae of suborder Soleoidei ,60 .35% in shortnose tongue-sole Cynoglossus abbreviatus and 60 .59% in half-smooth tongue-sole C .semilaevis .However ,the A ＋ T content from the family Soleidae of suborder Soleoidei （54 .63% in Senegalese sole Solea senegalensis） was found very similar to those of suborder Pleuronectoidei .The ratios of synonymous substitution （K a） to synonymous substitutions （Ks） （K a/Ks） in mitochondrial protein-coding genes were ranged from 0 to 0 .2171 in Hippoglossus ,Verasper and Cynoglossus ,indicating that there is a strong purification （negative） selection in Pleuronectiformes mitochondrial genomes . The comprehensive analysis of 12 Pleuronectiformes mitochondrial gene mutation features show s that nad5 ,nad4 and nad2 genes are ideal molecular markers . Mitochondrial gene order of nine species from the suborder Pleuronectoidei and Senegalese sole from the family Soleidae in suborder Soleoidei is a typical arrangement of vertebrate mitochondrial genomes . However , there are translocation and inversion of tRNA gene （trnQ ） in mitochondrial genomes of shortnose tongue-sole and half-smooth tongue-sole from the family Cynoglossidae of suborder Soleoidei . Mitochondrial genome data support the phylogenetic relationship within Pleuronectiformes at families level ： [（Pleuronectidae＋ Paralichthyidae）＋ Scophthalmidae）]＋ Soleidae） ＋ Cynoglossidae . The family Soleidae of suborder Soleoidei was clustered with the suborder Pleuronectoidei firstly （BPN = 100 , BPM = 100） ,followed by clustered with the family Cynog

关 键 词：基因排列 分子标记 系统发生 选择压力 鲆鲽类 

分 类 号：Q915.862[天文地球—古生物学与地层学]